Method of operating a navigation system to provide geographic location information

Abstract

A computer implemented method of operating a navigation system to provide geographic location information is provided. The method comprises receiving a query text string representing a query for a geographic location from a user and obtaining data records that represent a plurality of candidate geographic locations. The method computes a text matching score that indicates how much of the query text string matches a record text string of the candidate geographic location and applies a usage pattern weight to the text matching score to obtain an overall score value for the candidate geographic location. The candidate geographic locations are ranked based on the overall score values.

1. A computer implemented method of operating a navigation system to provide geographic location information, the method comprising:
 receiving a query text string representing a query for a geographic location from a user; 
 obtaining data records that represent a plurality of candidate geographic locations from a geographic database stored on a computer readable medium, each of the data records comprising a record text string; 
 computing a text matching score for each of the candidate geographic locations, wherein the text matching score indicates how much of the query text string matches the record text string; 
 for each of the plurality of candidate geographic locations, applying a usage pattern weight of one of the candidate geographic locations to the text matching score of one of the candidate geographic locations to obtain an overall score value for the one of the candidate geographic locations, wherein the usage pattern weight is increased when users have selected the one of the candidate geographic locations and decreased with a time fade out; and 
 ranking by computer the candidate geographic locations based on the respective overall score values, 
 wherein the overall score value s 0  is calculated from the usage pattern weight w′(f) and the text matching score s f  according to: 
 
       
         
           
             
               
                 
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         and wherein the time fade out is defined by a predetermined half-life of the usage pattern weight and an amount of time elapsed from a preceding time fade out. 
       
     
     
       2. The method of  claim 1  further comprising:
 providing the candidate geographic locations that have the highest overall score values; 
 receiving a selection of the one of the candidate geographic locations from the user; and 
 increasing the usage pattern weight for the one of the candidate geographic locations that was selected. 
 
     
     
       3. The method of  claim 2  further comprising:
 recording the selection of the one of the candidate geographic locations on a computer readable storage medium. 
 
     
     
       4. The method of  claim 1  wherein the time fade out is an exponential time fade out. 
     
     
       5. The method of  claim 1  wherein the data record that represents the candidate geographic location comprises a street field with a street text string and a city field with a city text string. 
     
     
       6. The method of  claim 5  wherein the text matching score comprises a street field score and a city field score. 
     
     
       7. The method of  claim 5  wherein the usage pattern weight comprises a usage pattern street field weight and a usage pattern city field weight. 
     
     
       8. The method of  claim 1  wherein the users select the one the candidate geographic locations by traveling to the one of the candidate geographic locations. 
     
     
       9. The method of  claim 1 , wherein the predetermined half-life of the usage pattern weight is one week.